1. Field of the Invention
The present invention relates to a specimen aliquoting/dispensing device for aliquoting a specimen, such as blood, from a test tube or some other specimen container that contains the specimen and dispensing the specimen into another specimen container.
2. Description of the Related Art
Pretreatment is performed before various blood tests, such as a biochemical analysis, are conducted. In this pretreatment, a test tube that contains a blood specimen is set in a centrifuge, whereby the specimen is centrifuged. Then, the blood serum in the test tube is aliquoted, and the aliquoted blood specimen is dispensed to a test container.
In general, the serum and clot of the centrifuged blood specimen in the test tube are generally separated in the test tube with use of a separating agent, such as silicone, so that an interface between the serum and clot portions can be clearly distinguished. Specifically, the centrifuged blood specimen is divided into three layers, the serum, separating agent, and clot, which are sequentially arranged from top to bottom in the test tube.
In aliquoting the serum in the test tube that is supported vertically, therefore, a tapered aliquoting/dispensing nozzle in the form of a hollow cone is inserted into the test tube, and only the serum is aliquoted by air suction by the nozzle. Then, the aliquoting/dispensing nozzle having aliquoted the serum is moved to another place, and the serum is dispensed to the test container.
Conventionally, an aliquoting/dispensing device for a specimen such as blood is known from Jpn. Pat. Appln. KOKAI Publication No. 6-323964. In this device, a head member is provided on the distal end portion of a sample supply/discharge pipe. The head member is provided with a balloon that is connected to a fluid supply/discharge pipe. This balloon is configured to be inflated or deflated with a fluid that is supplied or discharged through the fluid supply/discharge pipe.
The aliquoting/dispensing device is provided with an aliquoting/dispensing nozzle. A barrel portion is provided at the proximal end portion of the nozzle. If the fluid is supplied to the balloon through the fluid supply/discharge pipe with the head member including the balloon inserted in the barrel portion, the balloon is inflated and brought into close contact with the inner peripheral surface of the barrel portion of the nozzle. If the fluid in the balloon is discharged through the fluid supply/discharge pipe, on the other hand, the balloon is deflated and separated from the inner peripheral surface of the barrel portion of the nozzle. Thus, the head member and the aliquoting/dispensing nozzle can be attached to or detached from each other by inflating or deflating the balloon.
Further, a specimen aliquoting/dispensing device with an elastic bag is known from Jpn. Pat. Appln. KOKAI Publication No. 9-127130. The elastic bag is attached to the distal end portion of a body of an aliquoting/dispensing nozzle, and a fluid can be supplied to and discharged from it. If the fluid is supplied to the bag through a fluid supply/discharge pipe with the nozzle body including the bag inserted in a barrel portion at the proximal end portion of the nozzle, the bag is inflated and brought into close contact with the inner peripheral surface of the barrel portion of the nozzle. If the fluid in the bag is discharged through the fluid supply/discharge pipe, on the other hand, the bag is deflated and separated from the inner peripheral surface of the barrel portion of the nozzle. Thus, the nozzle body and the aliquoting/dispensing nozzle can be attached to or detached from each other by inflating or deflating the elastic bag.
In either of the devices described in Jpn. Pat. Appln. KOKAI Publications Nos. 6-323964 and 9-127130, however, the balloon is inflated or deflated by supplying or discharging the fluid so that it is pressed against or separated from the inner peripheral surface of the barrel portion of the aliquoting/dispensing nozzle, whereby the nozzle body and the nozzle are attached to or detached from each other. Since an additional device is needed to supply and discharge the fluid to and from the balloon, therefore, the construction of the nozzle device is complicated. Further, the balloon is expected to be inflated and deflated by the fluid supply and discharge, so that it should be formed thin-walled. Since the balloon is bound to rub repeatedly against the inner peripheral surface of the barrel portion of the nozzle, however, it is easily damaged by abrasion. Thus, the balloon requires troublesome maintenance work including frequency replacement.
Furthermore, the aliquoting/dispensing nozzle is attached to the nozzle body in a process for aliquoting the blood specimen in the test tube by means of the aliquoting/dispensing nozzle and dispensing the aliquoted specimen to another test container. Then, the blood specimen is aliquoted and dispensed by means of the nozzle. In doing this, however, the aliquoting/dispensing nozzle must be removed from the nozzle body and cast away every time the specimen is aliquoted and dispensed. This operation is so troublesome or complicated that the operating efficiency is poor, thus requiring automation.